Synthesis of AIZS@SiO 2 core-shell nanoparticles for cellular imaging applications

Abstract

I-III-VI 2 semiconductor nanoparticles such as AgInS 2 have been developed for cell imaging applications in recent years. However, there are few published works reporting the phase transfer (from hydrophobic to hydrophilic) of the AgInS 2 nanoparticles for biomedical application purposes. In this work, we report the successful silica coating for the as-synthesized Zn-doped AgInS 2 (AIZS) nanoparticles via a templated coating route. The silica shell thickness of the obtained AIZS@SiO 2 core-shell nanoparticles could be well controlled within 10-20 nm and their overall size was less than 50 nm. As compared to the AIZS nanoparticles stabilized by cetyltrimethylammonium bromide (CTAB), the obtained AIZS@SiO 2 nanoparticles showed much improved photoluminescence (PL) stability in water. The obtained core-shell nanoparticles were further conjugated with the PEG functional group, and the resultant PEGylated nanoparticles showed excellent colloidal stability in various media such as water, phosphate buffered saline (PBS) and bovine calf serum (BCS). The cellular imaging application of the obtained AIZS@SiO 2 nanoparticles was also demonstrated successfully. © The Royal Society of Chemistry 2012.